Glass grinding apparatus



Oct. 4, 1938. I WALDRQN 2,131,862

'GLAS S GRINDING APPARATUS Filed Jan. 28, 1958 ZIfiIZIZIZlIZII I Patented Oct. 4, 1938 GLASS GRINDING srraaa'rus Frederic Barnes Waldron, Prescot, England, as-

sig'nor to Pilkington Brothers Limited, Liverpool, England, a limited liability company Application January 28, 1938, Serial No. 187,398 In Great Britain February 1, 1937 6 Claims.

This invention relates to grinding apparatus operating simultaneously on both sides of a continuous strip of glass, and has for its object improved means for driving the strip through the apparatus.

Hitherto the strip has been driven by pairs of rollers gripping the glass strip, one or both of the rollers being driven. It has been found that sand from the grinding tools accumulates in the pass between each roller and the glass and causes damage as the result of undue pressure between the rollers and the glass and wear of the rollers. It has further been found impossible to clean the sand from the glass so effectively as to prevent this accumulation. 7

According to the invention a roller, having a plurality of grooves at the pass between the roller and the glass is combined with one or more water jets so placed as to maintain a layer of water in the pass between the roller and the glass, which is in continuous rapid motion.

In the accompanying drawing:

Figure 1 is a side view of part of a grinding a paratus; and

Figure 2 is a section thereof along the line A-A of Figure 1; and

Figure 3 is a view of an alternative form roller.

The glass strip I is driven in the direction of the arrow between the grinding tools 2, by pairs of rollers 3, 4 gripping the strip. The apparatus comprises generally about fifteen pairs of grinding tools, with a pair of driving rollers between each pair. It has been customary to remove the sand, which is used as abrasive, from the glass by means of a squeegee 5 and water jets 6, supplied from the water pipe I. The roller 3, which is generally made of rubber, is provided with a plurality of grooves 8, and water jets are so placed, close to the glass and to the roller, that the layer of water in the pass between the roller and the glass is kept in continuous motion.

Although the squeegee 5 and water jets 6 rer move nearly all the sand from the glass, it has been found that a certain quantity of sand passes the squeegee and, in the case of the usual cylindrical roller accumulates in the pass between the roller and the glass. By means of the water jets .9, the small quantity of sand which approaches the pass of the roller is kept in suspension in the continuous and rapidly moving layer of water. This layer of water flows along in the pass of the roller until it reaches a groove 8, and is then able to escape past the roller through the groove,

. carrying with it the sand which always remains in suspension.

It is essential that the quantity of sand which reaches the point indicated by ID in Figure 2 be so small that it does remain in suspension in the water, and it is therefore preferable that the squeegee 5 and water jets 6, or other sand removing device be retained. But, if the quantity of water used in the jets 9 be very large, this is suflicient to wash away, oil? the edges of the strip, nearly all the sand.

A single jet 9 may be employed if the velocity of'the water be sufilcient to maintain the water at the far end of the roller in rapid motion. Alternatively, a row of jets may be employed at different points along the roller.

Preferably, similar devices are employed on the underside of the strip, the roller 4 also having grooves. It is, however, possible to wash the underside of the glass clear of sand by water jets, since the sand and water can escape from the underside without having to flow to the edges of i the strip.

A single spiral groove such as H in the roller 3 of Figure 3 is deemed to be the equivalent of a plurality of circular grooves, since this presents a plurality of grooves along the line of contact between the roller and the glass, as does a roller with a plurality of circular grooves.

Having described my invention, I declare that what I claim and desire-to secure by Letters Patent is:

1. Apparatus for grinding a continuous strip of glass comprising grinding tools operating simultaneously on the upper and lower sides of the strip, and the combination with pairs of rollers between the tools adaptedto grip the strip and drive it between the tools of which at least the upper roller has a plurality of grooves at the pass between the said roller and the glass, of means for maintaining a layer of water in continuous and rapid motion in the said pass.

2. Apparatus for grinding a continuous strip of glass comprising grinding tools operating simultaneously on the upper and lower sides of the strip, and the combination with pairs of rollers between the tools adapted to grip the strip and drive it between the tools of which at least the upper roller has a plurality of circular grooves, of means for maintaining a layer of water in continuous and rapid motion in the pass between the said roller and the glass.

3. Apparatus for grinding a continuous strip of glass comprising grinding tools operating simultaneously on the upper and lower sides of the strip, and the combination with pairs of roll ers between the tools adapted to grip the strip and drive it between the tools of which at least the upper roller has at least one spiral groove, of means for maintaining a layer of water in continuous and rapid motion in the pass between the said roller and the glass.

4. Apparatus for grinding a continuous strip 01 glass comprising grinding tools operating simultaneously on the upper and lower sides of the strip, means adapted to remove the abrasive from the surfaces of the strip and the combination with pairs oi rollers between the tools adapted to grip the strip and drive it between the tools of which at least the upper roller has a plurality of grooves at the pass between the said roller and the glass, of means for maintaining a layer of water in continuous and rapid motion in the said Pass.

5. Apparatus for grinding a continuous strip of glass comprising grinding tools operating simultaneousiy on the upper and lower sides of the strip, means adapted to remove the abrasive from t the surfaces of the strip and the combination with pairs of rollers between the tools adapted to grip the strip and drive it between the tools of which at least the upper roller has a plurality of circular grooves, of means for maintaining a layer 01' water in continuous and rapid motion in the pass between the said roller and the glass.

6. Apparatus ior grinding a continuous strip of glass comprising grinding tools operating simultaneously on the upper and lower sides of the strip, means adapted to remove the abrasive from the surfaces oi the strip and the combination with pairs 01 rollers between the tools adapted to grip the strip and drive it between the tools 01' which at least the upper roller has at least one spiral groove, of means for maintaining a layer of water in continuous and rapid motion in the pass between the said roller and the glass.

FREDERIC BARNES WALDRON. 

